The hottest job skill is...

The Army, NYPD and State Department can't get enough workers with this job skill. Neither can Fortune 500 companies, hospitals, local courts and schools.

What is it? Fluency in a foreign language.

Translators and interpreters are expected to be one of the 15 fastest growing occupations in the nation, according to the Department of Labor.

Roughly 25,000 jobs are expected to open up for interpreters (who focus on spoken language) and translators (who focus on written language), between 2010 and 2020, the Department of Labor estimates. That represents 42% growth for the field and does not include the military, which is also recruiting ferociously for more people.

In the last week alone, roughly 12,000 jobs posted on Indeed.com included the word "bilingual."

Nationwide, workers in this field earn a median salary of $43,000 a year.

Far higher salaries go to people who work in the intelligence community on behalf of the military, the State Department, CIA, FBI or government contractors. These jobs can pay well into the six figures, as workers are required to pass high-level security clearances and enter dangerous situations.

"The government needs languages spoken in the Middle East and Africa. These people make the most money of all, but this is not just because of their language skills -- this is because of the high risk of the job," said Jiri Stejskal, spokesman for the American Translators Association. "They work in war zones. They may have a $200,000 salary but it's because they're willing to get shot at."

Not willing to put your life on the line? High salaries are also available to translators and interpreters who specialize in legal, medical, technical or scientific knowledge.

Which languages offer the highest returns?In government jobs, it's middle eastern languages like Arabic, Farsi and Pashto (Afghani). In the private sector, it's Scandinavian and Asian languages that pay.

In contrast, Spanish is the second most common language in the United States after English, and because it is so prevalent, it offers the lowest return.

Most interpreters and translators work on a freelance basis, which can be both a blessing and a curse. The work schedule can be flexible, it can be unsteady and come without benefits.

"Since the majority of people in our field work as independent contractors and run their own business, the volume of work of course is subject to fluctuations," said Dorothee Racette, a German-English translator and president of the American Translators Association. "Compensation varies a lot based on language combination, years of experience, area of specialization, and the country or region where customers are located."

Interpreters tend to get paid by the hour, half-day or day, with a range of $300 to $1,000 per day. The highest caliber interpreters are often certified by the International Association of Conference Interpreters, and can command the largest wages, Stejskal said.

Get paid thousands to stay in bed

Translators, on the other hand, are usually paid by the word. The average rate for translating the 30 most commonly used languages on the web was 13 cents in 2012, according to market research firm Common Sense Advisory. Rarer languages command higher per-word rates but also tend to be lower in demand.

Speed is crucial to making the highest salary. For example, good translators who can do 2,500 to 3,000 words a day, would earn $325 to $390 a day, whereas a newbie to the field may be capable of far less.

Kari Carapella, a senior recruiter for staffing firm Adecco Engineering & Technical, is currently trying to fill a job for an engineering translator in Big Falls, NY. The ideal candidate must not only be fluent in Japanese, but also understand electrical and mechanical engineering blueprints and documents.

"It's especially tough to fill as both the technical and translation skills must be in place," she said.